Discombobulate

This is a word that everyone should know. I don't know why Webster 1913 didn't autonode it, because it reportedly is an American English invention, first seen in the early 1800s and still used today. It's thought to have evolved from discompose or disconcert, perhaps being merged with bobbery. Since the word was a modification of an existing dis- word, it follows that there is no word combobulate.